Abstract: An assembly body structure project generation method by key structures is presented. An assembly body can be decomposed into assembly body structures and assembly body structure units based on assembly determinacy, Basic assembly body structures and assembly body structure units are used as the key structures of assembly body, the connected relations, qualitative spatial relations between function surfaces which belong to integrant contained components in different key structures, and their types are used to represent the connected relations among key structures. The adjacency and combinatorial conditions among key structures, the extension method of adjacency conditions, the judgment method of assembly certainty in combinatorial projects are discussed. The strategy that the replaceable key structures are removed first and then displaced after combinatorial projects are formed is adopted. The family of key structure combinatorial projects is formed after displacing of replaceable key structures. On the basis of referring to algorithm on compounds isomer exhaustive generation and redundancy analysis, the combinatorial design of structure projects is realized. The method is validated by taking valve rod assemblies as example.

Key words: combinatorial design, key structure, structure project